Sewing machine for corner stitching



May 30, 1944.

KW imam SEWING MACHINE FOR CORNER STITCHING Filed Nov. 1

3 Sheets-Sheet 1 5 0m joiub allot/m May 30, 1944. zoms 2,350,267

SEWING MACHINE FOR CORNER STITCHING zw W May 30, 1944.

s. zoNls 4 2,350,267

SEWING MACHINE FOR CORNER STITCHING Filed NOV. 13, 1942 r 3 Sheets-Sheet3 Syd 07266 Patented May 30, 1944 SEWING MACHINE FOR CORNER STITCHINGSydney Zonis, Bridgeport, Conn, assignor to .The

Singer Manufacturing Company,

Elizabeth,

N. J a corporation of New Jersey Application November 13, 1942, SerialNo. 465,415

1.7 Claims.

This invention relates'to sewing machines and more particularly tosewing machines employed for producing angular or corner seams, i. e.,for producing stitched seams in which a line of stitches continues abouta sharp corner into another line of stitches.

In employing sewing machines for making angula seams, as for examplesubstantially rightangled seams, it has been heretofore the commonpractice toposition the needle in the work, after stopping the machine,so as to turn the work about the needle after the looper or loop-takerhas seized the needle-thread loop. This procedure was necessitated bythe fact that the tuming of the work about the needle resulted in alsowrapping about the needle the Work-limb or the needle-thread loopextending from the needleeye and anchored to the work; whereby theneedle failed properly to present the needlethread loop for entrance bythe looper or looptaker.

In employing chain-stitch sewing machines for making angular seams, anadditional difficulty heretofore existing arose from the fact that,

when the work was turned about the needle, the thread-loop previouslyseized by the looper or held spread by'the looper'was-bent about a sideedge of the needle-slot in the work-support, thereby tensioning thethread-loop sufiiciently to result in thread-breakage, or in stealingthread needle beyond the needle-eye, thereby substantially to increaseproduction and the quality of the product.

With this and other objects in View, as will hereinafter appear, theinvention comprises the devices, combinations and arrangements of partsdescribed in connection with the accompanying drawings which illustratea preferred embodiment of the invention and in which:

Fig. 1 is a front end elevation of a chain-stitch sewing machinecontaining the present improvement, the bed-plate being shown invertical section and the bracket-arm being partly broken away. Fig. 2 isa bottom plan view of a portion of the machine in the region of theneedle, the looper being broken away to expose the thread.- positioningmember. elevation, partly in vertical section, of the stitchforming andwork-feeding instrumentalities Fig. 3 is an enlarged end with the needlein substantially its lowest position while in the work; the feed-dogbeing'sedtioned longitudinally of the left hand row of the teeth thereofand the work being sectioned in the line of seam formation. Fig-4 is afront side elevation, partly in vertical section, of the stitchforminginstrumentalities in the position thereof illustrated in Fig. 3; thesection being taken substantially through the needle path ofreciprocation crosswise of the line of feed. Fig. 5 is a View similar toFig. 3, but with the work turned to the left about the needle. Fig.6 isa. View corresponding to Fig. 4,'but with the work turned about theneedle as in Fig. 5. Fig. 7 is a view corresponding to Fig. 6, but'in anupstroke position of the needle in which the work-limb of theneedle-thread loop is bowed outwardly and entered by'the looper. Fig. 8is a top plan View of the mechanism as illustrated in Fig. 7; the needle:being shown in section and the finished stitches being shown partly insection as disposed substantially normal to the line of seam formation.Fig. 9 is an enlarged fragmentary topplan view of the work-support,feed-dog and looper, and illustrates the needle-thread loops (partly insection) in the loop-casting-off position of the looper. Fig. 10 is anenlarged fragmentary view in top plan of the needle-thread positioningmember, with the needle and needlethread shown in horizontal section,and the needle-slot of the work-support shown in dot-' dash lines.throat-plate. the needle-thread positioning member. is a perspectiveView of the feed-dog.

The present invention is illustrated in the drawings as embodied in thesingle-thread chainstitch sewing machine more completely disclosed Fig.11 is a perspective View of the Fig. 12 is a perspective view of Fig. 13

in the pendingpatent application of S. Zo-nis et al., Serial No.381,242, filed Mar. 1, 1941.

Referringto'the drawings, the sewing machine in part shown has a frameincluding a bedplate I provided with a throat-plate 2 which, in

conjunction with the upper face of the bedplate, forms a work-support.overhanging the bed-plate l is a bracket-arm terminating at its free endin ahead 3.

Journaled in the bracket-arm head 3 is an end wise verticallyreciprocatory needle-bar and an endwise vertically movable presser-bar5. The needle-bar 4 carries at its lower end an eyepointed needle 6,while the presser-bar 5 carries at its lower end a presser-foot I; saidpresserbar 5 being spring-depressed in any usual or suitable manner;

Complemental' to the needle '6, below the worksupport and in theformation or single-thread chain-stitches, is a rotary wing-type looper8 of conventional form. The looper 8, as usual, has a curvedloop-seizing beak 9 merging into a loopexpanding body I which terminatesin a transverse loop-detaining throat ll. Extending rearwardly beyondthe throat II is a loop-twisting and spreading wing l2 for holding theseized and spread needle-thread loop in position for subsequent entranceby the beak 9 of the looper. The looper 8 has a shank-pin l3 entering anend bore of a rotary looper-shaft l4, to which shaft the shank-pin I3 issecured by a screw IS. The looper-shaft also carries the usualspacing'collar I 6, secured to the shaft by a screw I1 and disposedadjacent the looper. The looper-shaft I4 is journaled horizontally atthe under side of the bed-plate I and is suitably driven to perform onerotation for each complete reciprocation of the needle.

The throat-plate 2 is provided with a needleslot l8 which is elongatedin the line of seam formation to extend rearwardly a substantialdistance beyond the path of reciprocation of the needle 6; the needlehaving its path of reciprocation at the forward end of the needle-slot[8.

The throat-plate 2 is also provided with a plurality of feed-slots I9,20, 2| and 22; the middle feed-slots and 2i being alined andrespectively disposed forwardly and rearwardly of the needle-slot I 8 inthe line of seam formation. The feed-slot I8 is disposed at the righthand side of the needle-slot I8; said feed-slot beginning from adjacentthe forward end of the needle-slot I8 and terminating at itsrearward endadjacent the rearward end of the feed-slot 2|. The feedslot 22 isdisposed at the left hand side of the needle-slot l8 and preferablyextends from adjacent the forward end of the feed-slot 20to adjacent therearward end of the feed-slot 2|.

Operating through the described throat-plate feed-slots is a feed-dog 23which is .opposed in the work-engaging movements thereofby thepresser-foot l. The feed-dog 23 has a right hand row of teeth 24suitable to operate through the feed-slot 19; a middle front row ofteeth 25 suitable to operate through the feed-slot 20; a

middle rear row of teeth 26 suitable to operate through the rearfeed-slot 2|; and a left hand row of teeth 2! suitable to operatethrough the feed-slot 22.

The upper face of the throat-plate 2 is cut away or depressed betweenthe needle-slot l8 and the feed-slot 22 to provide in the work-support athread-clearance recess 28 which pref- 1 erably begins slightlyrearwardly of the forward end of said needle-slot; thereby to leaveadequate support for the work adjacent the needle path. The edgedefining the forward end of the recess 28 is preferably inclinedforwardly toward the feed-slot 22; and the bottom wall of the recess 28is gradually curved upwardly at the rearward end of said recess to mergegradually into the upper face of the throat-plate 2.

The left hand row of teeth 21 of the feed-dog 23 is also interrupted orcut away between the ends of the row to provide a thread-clearancedepression or recess 29 adjacent to and forming a continuation of thethroat-plate recess 28.

The feed-dog 23 is carried by a feed-bar 30 disposed below thework-support. The rearward end of the feed-bar 30 is pivotally connectedto a feed-rocker 3| rising from a feedadvance rock-shaft 32 which may besupported and actuated in any usual or suitable manner.

The forward end of the feed-bar 30 is forked to slidably embrace apivot-block 33 carried by a crank-arm 34 extending rearwardly from afeedlift rock-shaft 35 which may likewise be supported and actuated inany usual or preferred manner in timed relation to the movements of thefeed-advance rock-shaft 32 to impart intermittent work-advancingmovements to the feeddog 23.

In order to insure the requisite cooperation between the needle 6 andthe looper 8, in the seizure of needle-thread loops by the looper, thereis employed a needle-guide 36 bent upwardly from its shank 31; saidshank 31 being attached by a screw 38 to the under side of the bed-platel. The needle-guide 38 has a needle-deflecting face 39 inclineddownwardly to merge into a substantially vertical needle-abutment face40 disposed at the long-groove side of the needle, i. e., the face 48 isdisposed at the side of the needle opposite to that at which the looper8 enters the needle-thread loops. Being disposed in close proximity tothe path of needle-recipro- 1 cation, the face 40 of the needle-guideserves as an abutment inducing the opening of the needle-thread loops atthe looper side of the needle, in the rising movement of the needle.

As is well understood in the art, the looper 8 'enters the needle-threadloop a, b between the needle 6 and the needle-thread loop-limb b whichis anchored in the work. This limb b of the needle-thread loop istherefore commonly termed the work-limb; while the other limb a 1 -ofthe needle-thread loop, at the opposite side of the needle is commonlytermed the take-up limb, because it extends through the work to theneedle-thread take-up (not shown).

The throat-plate 2 is recessed in its under face and at the looper-beakside of the needle-path to form a seat 4| for the shank 42 of an endwiseadjustable needle-guiding and thread-loop positioning member 43; saidmember 43 being attached in set position to the throat-plate 2 by screws44 passing through a slot 45 formed lengthwise in the shank 42. Theparallel side edges of the seat 4|, which confine the shank 42 toendwise adjustment, are inclined rearwardly at an angle of approximatelyto the line of seam formation.

The member 43 extends in front of and across the throat-plate feed-slotI9 toward the path of needle reciprocation. Near its free end, themember 43 has a needle-guiding and threadloop positioning edge 46 whichis rearwardly inclined, preferably at an angle of approximately 10,toward the line of seam formation. The edge 46 of the member 43 extendspartly across the throat-plate needle-slot l8 and slightly past theneedle-path in close proximity to said path at the needle-thread-loopwork-limb side of said path, whereby said edge 46 is disposedsubstantially tangential to the needle 5 rearwardly of said work-limb bof the needle-thread loop in any work-penetrant positions of said needlebeyond the needle-eye. The edge 46 preferably terminates at its rearwardend substantially in the plane containing the line of seam formation andthe path of needle-reciprocation. By endwise adjustment of the member43, the edge 46 thereof may be shifted laterally toward and from thepath of needle-reciprocation in a direction inclined to the length ofthe needle-slot l8 of the throat-plate 2.

Merging into the rearward end of the threadloop positioning edge 48 is athread-loop castacumen? off edge. .41' inclinedrearwardly away .from theline "of iseam formationat "the ;edge 46 side of said line; the.cast-off-edge 41 is therefore dis posed at the work-limb b side of theline of seam formation and is inclined in a directionoppositely to thedirection ofrinclination of the As the needle 6 is held by theneedle-guide 36 against deflection away from the edge 46, and as theedge 46 is substantially tangential to the needlepath directly to therear of the work-limb .1).

said work-limb b is restrained by the complemental action of the needle6 and the edge'46 from passing rearwardly therebetween in anywork-penetrating position of the needle beyond the needle-eye.

This condition is particularly of advantage when the work is turnedabout the needle in the production of angular or'corner seams, *becausethe work-limb b is thereby restrained from wrapping about the needle 6at any point below the member 43, whereby the work-limb b of theneedle-thread loop will be properly opened out and presented for seizureby the looper. In other words, the present invention provides for turning the work about the needle for corner-stitching, in anywork-penetrant position of the needle, because the work-limb willinevitably be crowded forwardly and positioned properly for seizure bythe looper.

The stitch-formation is illustrated in Figs. 13 to 9 inclusive of thedrawings. In Fig. 3, the work 10 is shown as being advanced in the lineof seam formation; the needle 6 being shown at substantially the lowerend of its stroke. The previously seized and spread thread-loop a, b isheld opened out .rearwardly of the needle 5 by the throat I! of thelooper 8, and the beak 9 of the looper is shown approaching the needle.As it is essential that the thread-loop a, b is at this time positionedto therear of the need-1e, it is equally essential that the upper end ofsaid thread-loop a b must have been free to move lengthwiseof thethroat-plate needle-slot 18 during the previous feeding movement of thework. As the needle 6 is out of the work during the feeding of the work.the present worklimb positioning device leaves the thread-loop a 1) freeto advance rearwardly in the needleslot 18 during said feeding of thework.

Fig. 4 of the drawings illustrates the same position of the parts as inFig. 3, but as viewed from the front of the machine. served that theabutment face 40 of the needleguide 36 is opposed to the needle-guidingand thread-positioning member 43, whereby the needle 6 is constrained toreciprocate in such ing of thework about the needle 6, the portion Itwill be obof said work-limb b below the member 43 remains in theposition which, as shown by comparison with Fig. 4, is the same asbefore the work was turned.

Nowwhen the needle begins to rise, as illustrate'd in Figs. 7 and 8, theWork-limb 1) opens out in. proper. position for seizure by thelooperbeak 9', even though the work has been turned about the needle 6.This condition will obviously be obtained when the work is turned aboutthe needle in any work-penetrant position of the needle. By thuseliminating any requirement to critically position the needle beforeturning the work, production is very substantially increased.

In chain-stitch sewing machines, such as the basting machine in whichthe present invention has been embodied and which are designed to makelong stitches, the limbs a b of the threadloop held. spread by thelooper are bent sharply about a .side edge of the needle-slot l8 byturning the work about the" needle. This is due to the fact that thelength of the stitches is greater than'the width of the needle-slot l8.By thus bending .the thread-loop a b about the edge of the needle-slotIS the thread-loop is likely to become sufficiently tensioned to resultin skippingrof stitches or in fact thread-breakage. This condition is tosome extent aggravated by the thread holding action of the positioningmember 4'3.

In accordance with the present-invention, the described recesses 28 and29 in the throat-plate and feed-dog. adjacent the needle-slot 13,provide sufficient thread-clearance to render negligible'the tensionimposed upon the'thread when the work is turned to the left about theneedle. This? is clearly illustrated in Figs. 5 to 8 of the drawings,which show the upper endsof the looplimbs a, b as lying in the recesses28 and 29.

Bythus easing the tension imposed upon the thread, there is lesstendency for the work-limb b of the needle-thread loop to 'passrearwardly between the needle" 3 and the member 43 when turning the Workabout the needle.

When thethread-loop a, b is cast off by the looper, the-limbo thereofunderlies the cast-off edge 4'! which is obtusely inclined to thethreadpositioningedge '46 of the member 43. This positionof.the-"thread-loop a, b is illustrated in Fig. 9 ofv the drawings. Owingto the relationsh-ipto-eachother of the edges 46 and 41, thethread-doopu, b is free to be drawn up to the workto set the stitch,without incurring any liabilityof the thread-loop being snagged by theconvergence corner of said edges.

Having thus set forth the nature of the invention'whatI claim herein is:

1-. In a sewing machine adapted for producing angular stitched seams, incombination, a work- 'support having a needle-opening, an endwisereciprocatory eye-pointed needle operating through said needle-opening,means complemental to-"Said .needle responsively to turning of the workin one direction about the needle;

2'; In asewing machine adapted for producing angular stitched seams, incombination, a worksupport provided with a need1e-slot elongated intheline of scam formation, wcrk feeding means for advancing workrearwardly'of said needleslot, an endwise reciprocatory needle operatingthrough the forward end portion of said needle-slot, said needle havinga thread-receiving eye extending crosswise of said needle-slot, a rotarylooper disposed below said work-support and having a loop-seizing beakand a loop detaining wing constructed and arranged to enchain loops ofthread presented by said needle, and means for restraining the work-limbof the needle-thread loop from wrapping rearwardly about the needlebetween the needle-eye and the work in any work-penetrant positions ofthe needle beyond the needle-eye and responsively to turning of the Workabout the needle, said means comprising a thread-positioning membercomplemental to said needle in blocking rearward movement of saidwork-limb.

3. In a sewing machine having a work-support provided with aneedle-opening, work-feeding means, an endwise reciprocatory needleoperating through said needle-opening and having a thread-receiving eye,and means complemental to said needle in the formation of stitches, theimprovement which consists in the provision in the region of saidwork-support of a member having a substantially straight needle-threadpositioning edge extending past the path of needle-reciprocation at theneedle-thread-loop worklimb side of said path and at an angle inclinedrearwardly toward the line of seam-formation,

said edge being disposed substantially tangential to said needlerearwardly of said work-limb in any work-penetrant positions of saidneedle beyond the needle-eye.

4. The construction set forth in claim 3, in which the needle-threadpositioning edge terminates at its rearward end substantially in theplane containing the path of needle-reciprocation and the line of seamformation.

5. The construction set forth in claim 3, in

which the needle-thread positioning edge of the member is inclinedrearwardly at an angle of approximately 10 to the line of seamformation.

6. The construction set forth in claim 3 in which the needle-threadpositioning edge is adjustable toward and from the path of needlereciprocation.-

'7. In a sewing machine, in combination, a work-support provided with aneedle-opening, work-feeding means, an endwise reciprocatory needlehaving a thread-receiving eye extending crosswise of the line of feed,means complemental to said needle in the formation of stitches, and amember having a needle-thread positioning edge disposed at theneedle-thread-loop worklimb side of the line of seam formation forengagement by the needle rearwardly of said worklimb in anywork-penetrant positions of said needle beyond the needle-eye, said edgeterminating substantially in the plane containing the path ofneedle-reciprocation and the line of seam formation.

tions of said needle beyond the needle-eye, and

means for detachably securing said member to the under side of saidwork-support.

9. In a sewing machine, in combination, a

;' work-support provided with a needle-slot, feeding means for advancingwork lengthwise of said needle-slot, an endwise reciprocatory needleprovided crosswise of said needle-slot with a thread-receiving eye, alooper complemental to said needle in the formation of stitches, amember having a needle-thread positioning edge extending partly acrosssaid needle;

slot from the work-limb side of the needle-thread loop into closeproximity to the rearward side 'of the needle path of reciprocation, andmeans for securing said member to said work-support for adjustment ofsaid edge with respect to said needle-path.

10. The construction set forth in claim 9 in .which the-thread-looppositioning edge of the member is laterally adjustable in a directioninclined to the length of the needle-slot of the Work-support.

11. In a sewing machine, in combination, a work-support provided with aneedle-slot, feeding means. for advancing work lengthwise of saidneedle-slot, an endwise reciprocatory needle provided crosswise of saidneedle-slot with a thread-receiving eye, a looper complemental to saidneedle in the formation of stitches; a stationary member disposed in theregion of said work-support and having a needle-thread positioning edgeextending past the needle-path at the work-limb side of theneedle-thread loopgated in the line of seam formation, an endwisereciprocatory needle operating through and 8. In a sewing machine, incombination, a

work-support provided with a needle-slot, feeding means for advancingwork lengthwise of said needle-slot, an endwise reciprocatory needlehaving a thread-receiving eye extending crosswise of said needle-slot, alooper complemental to said needle in the formation of chainstitches, amember having a needle-thread positioning edge extending from theneedle-threadloop work-limb side of the line of seam formation forengagement by the needle rearwardly of said work-limb in anywork-penetrant posihaving a thread-receiving eye extending crosswise ofsaid needle-slot, a looper complemental to said needle in the formationof stitches, and.

a stationary member having thread-positioning and thread-loop cast-ofi'edges oppositely inclined to the line of seam formation at the worklimbside of the needle-thread loop, said edges merging together in theregion of said work-support rearwardly of and in close proximity to thepath of needle reciprocation.

13. In a sewing machine, in combination, a work-support provided with aneedle-slot elongated in the line of seam formation, an endwisereciprocatory needle operating through and having a thread-receiving'eyeextending crosswise bf said needle-slot, a looper complemental to saidneedle in the formation of stitches, a stationary thread-positioningedge rearwardly inclined to the line of scam formation at the worklimbside of the needle-thread loop and extending into tangential relationwith the needlepath rearwardly of the needle-eye, and a stationarythread-loop cast-off edge inclined rearwardly away from the line of seamformation at the work-limb side of said needle-slot, said castoff edgemerging into the rearward end of said thread-positioning edge, and beingdisposed in the region of, said work-support. v

14. In a sewing machine having a work-support provided with aneedle-slot and a feedslot lengthwise parallel to and disposed at oneside of said needle-slot, a feed-dog having workengaging teeth operatingthrough said feed-slot, an endwise reciprocatory needle operatingthrough said needle-slot, said needle having a thread-eye extendingcrosswise of said needleslot, and a looper cooperating with said needleat the side thereof opposite to said feed-slot in the formation ofchain-stitches, the improvement which consists in the provision in theworkengaged face of said work-support of a threadclearance recessextending from said needle-slot to said feed-slot, and in the provisionin the teeth of said feed-dog of a thread-clearance recess adjacent toand forming a, continuation of the recess of said work-support, therebyto provide clearance for the thread-loop extending from the work to thelooper when the work is turned about the needle.

15. In a sewing machine, in combination, a Work-support provided with aneedle-slot and a feed-slot lengthwise parallel to and disposed at oneside of said needle-slot, a feed-dog having work-engaging teethoperating through said feed-slot, an endwise reciprocatory needleoperating through said needle-slot, said needle having a thread-eyeextending crosswise of said needle-slot, a looper cooperating with saidneedle at the side thereof opposite to said feed-slot in the formationof chain stitches, said work-support being provided in the work-engagedface thereof with a thread-clearance recess extending from saidneedle-slot to said feed-slot, and said feed-dog being cut away toprovide the workengaging portion thereof with a thread-clearance recessadjacent to and forming a continuation of the recess of saidwork-support, said recesses providing clearance for the thread-loopextending from the work to the looper when the work is turned about theneedle, and a thread-positioning member complemental to said needle forrestraining the work-limb of the needle-thread loop from wrappingrearwardly about the needle between the needle-eye and the work in anyposition of the needle while in the work and responsively to turning ofthe work about the needle.

16. In a sewing machine, in combination, a work-support provided with aneedle-slot and a feed-slot lengthwise parallel to and disposed at oneside of said needle-slot, a feed-dog having work-engaging teethoperating through said feed-slot, an endwise reciprocatory needleoperating through said needle-slot, said needle having a thread-eyeextending crosswise of said needle-slot, a rotary looper disposed belowsaid worksupport and having a loop-seizing beak and a loop-detainingwing, said looper rotating in timed relation to the reciprocations ofsaid needle to carry each newly seized needle-thread loop through thepreviously seized needle-thread loop held spread by the looper, saidwork-support being provided in the work-engaged face thereof with athread-clearance recess substantially coextensive with the length ofsaid needle-slot and extending from said needle-slot to said feed-slot,and said feed-dog being cut away to provide the work-engaging portionthereof with a threadclearance recess adjacent to and forming acontinuation of the recess of said work-support, said recesses togetherproviding clearance for the thread-loop extending from the work 'to thelooper when the work is turned about the needle, and athread-positioning member compleznental to said needle for restrainingthe work-limb of the needle-thread loop from wrapping rearwardly aboutthe needle between the needle-eye and the work in any position of theneedle while in the work and responsively to turning of the work aboutthe needle.

1'7. In a sewing machine, in combination, a work-support having aneedle-opening, workfeeding means, an endwise reciprocatory eyepointedneedle operating through said needleopening, means complemental to saidneedle in the formation of stitches, a stationary member having aneedle-guiding and thread-loop positioning edge disposed substantiallytangential to said needle in the region of said work-support andrearwardly of the needle-thread-loop limb anchored in the work, and aneedle-guide disposed at the side of the needle opposite to said edge insufiiciently close proximity to said needle to maintain the tangentialrelation of said edge with the needle.

SYDNEY ZONIS.

